app.py

import gradio as gr
import torch
import transformers
import spaces
from synthid_text import  synthid_mixin,logits_processing
from synthid_text.detector_mean import mean_score

# Configurations and model selection
MODEL_NAME = "google/gemma-7b-it"
DEVICE = torch.device('cuda:0') if torch.cuda.is_available() else torch.device('cpu')
TOP_K = 40
TOP_P = 0.99
TEMPERATURE= 0.5

# Initialize model and tokenizer
# model = synthid_mixin.SynthIDGemmaForCausalLM.from_pretrained(
#     MODEL_NAME,
#     device_map=DEVICE,
#     torch_dtype=torch.bfloat16,
# )
tokenizer = transformers.AutoTokenizer.from_pretrained(MODEL_NAME)
tokenizer.pad_token = tokenizer.eos_token
tokenizer.padding_side = "left"

# Watermarking configuration
CONFIG = synthid_mixin.DEFAULT_WATERMARKING_CONFIG



# Function to check for AI-generated content using SynthID and highlight watermark
@spaces.GPU
def check_plagiarism(text):
    # Logits processor for SynthID
    logits_processor = logits_processing.SynthIDLogitsProcessor(
        **CONFIG, top_k=40, temperature=0.5
    )
    
    # Tokenize and process the input text
    inputs = tokenizer(text, return_tensors="pt").to(DEVICE)
    
    # Extract token IDs for the input text only
    input_ids = inputs['input_ids']

    # Compute masks for watermark detection
    eos_token_mask = logits_processor.compute_eos_token_mask(
        input_ids=input_ids,
        eos_token_id=tokenizer.eos_token_id,
    )[:, CONFIG['ngram_len'] - 1:]
    
    context_repetition_mask = logits_processor.compute_context_repetition_mask(
        input_ids=input_ids
    )
    
    # Combine the masks
    combined_mask = context_repetition_mask * eos_token_mask
    
    # Compute G values for the input text
    g_values = logits_processor.compute_g_values(input_ids=input_ids)
    
    # Score the G values with the combined mask
    score = mean_score(g_values.cpu().numpy(), combined_mask.cpu().numpy())
    
    # Initialize string to store highlighted output
    highlighted_text = ""
    
    # Loop through each token in the input text and apply highlighting if it meets the watermark criteria
    for token_id, g_val, mask in zip(input_ids[0], g_values[0], combined_mask[0]):
        token_text = tokenizer.decode(token_id.unsqueeze(0))
        
        # Convert g_val to float and highlight if it meets the threshold
        if mask.item() and g_val.float().mean().item() > 0.55:
            highlighted_text += f"<mark>{token_text}</mark>"  # Highlight watermarked content
        else:
            highlighted_text += token_text

    # Return the highlighted text and overall watermark score
    if score > 0.5:
        return f"Flagged as AI-generated content (Academic Integrity Warning): {highlighted_text}"
    else:
        return f"Content appears to be human-generated. {highlighted_text}"


# Define the Gradio interface
def create_plagiarism_checker():
    with gr.Blocks() as app:
        # Add custom CSS styling using gr.HTML
        gr.HTML("""
            <style>
                #text_input { font-size: 16px; border: 1px solid #ddd; padding: 8px; }
                #output { font-size: 16px; padding: 8px; border-radius: 5px; }
                #check_button { font-size: 16px; background-color: #4CAF50; color: white; border: none; padding: 10px 20px; cursor: pointer; }
                #check_button:hover { background-color: #45a049; }
            </style>
        """)

        # Title and description
        gr.Markdown("""
            # 📝 Plagiarism and Academic Integrity Checker
            Use this tool to detect AI-generated content in your text using SynthID technology. 
            Paste your text below to check if it contains AI-generated segments.
            ---
        """)

        # Layout the components
        with gr.Row():
            # Input textbox for users to paste text
            text_input = gr.Textbox(
                placeholder="Paste your text here...",
                label="Input Text",
                lines=10,
                max_lines=20,
                elem_id="text_input",
            )
        
        # Divider for clarity
        gr.Markdown("---")

        # Output box to display the result with highlighted watermark
        output = gr.HTML(label="Integrity Check Result", elem_id="output")

        # Button to initiate the check, styled with a color accent
        check_button = gr.Button("🔍 Check Text", elem_id="check_button")
        
        # Define the click event for the button
        check_button.click(fn=check_plagiarism, inputs=text_input, outputs=output)

    return app

# Launch the app
plagiarism_checker_app = create_plagiarism_checker()
plagiarism_checker_app.launch()